One downside, is that the current Qantas domestic terminal is probably the best of the three, and if Mac takes that over it may all become the same style of shopping plaza we have come to enjoy elsewhere in Sydney Aiport.
A good note, although is this a dig at the
style of T1 or do you mean how there are so many shops (and how the Duty Free has been "strategically" placed at T1) and it doesn't blend nicely?
The "shopping centre" look is hard to get away from. There are really two (or really one-and-a-half) approaches. One is you have the "shopping mall" and then a "dead zone" edge, i.e. gate areas. This is similar to LHR T3, BKK, KUL and KIX. Another is that you have the huge shopping mall and gates that stick out from it. SYD T1 is kind of like this for most areas, as are places like DXB and SIN.
What annoys everyone to bits are, of course, how Duty Free neatly is placed after immigration and, in the case of the "*A pier", also smack in the middle of the concourse. They don't make it a straight beeline path either - oh no, they put all the twists and turns into it. Even if QF retain ownership of T3 (and the odds of this are probably at best even money), if they have to convert it (or T2 for that matter) into an international airport, then I think we'll see the same thing with the duty free happen as it has with the other two major Australian international gateways, and always will. Who knows - they will probably find more "novel" (read "insidious") ways to set it up. And unfortunately business and marketing theory has shown that the set up is extremely effective in improving duty free sales (more time in the shop = more chances to buy, an inevitable conclusion; and those annoyed at the idea, well, can please themselves). This factor alone is probably what stops QF from actually making some sort of exclusive beeline lane that cuts through to the lounge (don't we all miss the timber staircase), e.g. straight from check-in to immigration (dedicated) to security (dedicated) to lounge, i.e. because (a) SACL/MAP and the duty free sales won't allow them to do that (miss out on customers), and (b) even if it were to happen at T3, the duty free sales outlet will complain that they are helping move potential customers away and will either launch a legal challenge or demand a premium per passenger due to lost sales.
So, the duty free shop after security is probably here to stay, irrespective of which terminal you travel through for your international flight. LHR T3 is just like this (and geez what a mess in traffic flow it causes).